Gov. Jerry Brown has committed to expanding the state's Medicaid program for low-income residents as prescribed by the federal health law, but his suggestions for how to do that could put more of the expense of doing so onto counties.

As part of his budget proposal last week, Brown offered two ways to make the program more widely available to poor adults with no dependent children and who did not qualify under the traditional rules for the health program, known as Medi-Cal in California.

Under one option, the state would run the expanded program but the counties would have to give up some funding. In the other scenario, the duties of running the program would fall to the counties. Either way, the counties could be taking on more responsibility for extending care to about a million more residents statewide over the next five years.

While counties play a key role in delivering health care to the indigent, the county-run option would mark a fundamental change to Medi-Cal and a divergence from the state-run expansion laid out in the federal health law.

California has been aggressive in implementing the 2010 federal health law, becoming the first state in the nation to set up its exchange, a virtual marketplace where uninsured consumers will be able to buy health insurance starting Jan. 1, 2014.

The law also covers more of the uninsured by expanding the state-federal Medicaid programs. More than 500,000 low-income Californians already receive expanded coverage through a program under the new law known as Bridge to Reform, which is run by counties with the help of federal funds. That program is scheduled to disappear at the end of the year, and those residents would be absorbed into Medi-Cal.

But the state's position on expanding Medi-Cal looked murky in the wake of the state's budget crisis and a U.S. Supreme Court decision that made the states' decision to expand the program optional.

The governor's budget proposal sets aside some $350 million in his 2013-14 budget plan to help pay for the costs of covering those who are currently eligible but not yet enrolled in the program.

California health officials say the counties would also benefit from the influx of federal funds as well as the reduced number of uninsured, but could lose some funds that have been available to their health programs for more than two decades.

If the counties are left in charge, their low-income health programs will be expanded, but they will have to adhere to federal law, leaving them with less leeway in setting many of the rules.

Tangerine Brigham, deputy director of the San Francisco Department of Public Health, said one thing remains clear. "There will still be uninsured individuals after 2014 and, generally, those uninsured individuals will turn to county safety nets," she said.